21270907 has 4 divisors (see below), whose sum is σ = 24309616. Its totient is φ = 18232200.

The previous prime is 21270881. The next prime is 21270919. The reversal of 21270907 is 70907212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21270907 - 2⁷ = 21270779 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21270947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1519344 + ... + 1519357.

It is an arithmetic number, because the mean of its divisors is an integer number (6077404).

Almost surely, 2^21270907 is an apocalyptic number.

21270907 is a deficient number, since it is larger than the sum of its proper divisors (3038709).

21270907 is an equidigital number, since it uses as much as digits as its factorization.

21270907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3038708.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 21270907 is about 4612.0393536916. The cubic root of 21270907 is about 277.0737204245.

The spelling of 21270907 in words is "twenty-one million, two hundred seventy thousand, nine hundred seven".